Today, my Ubuntu 14.04 froze after suspending, so I had to hard-reboot it. When it rebooted, the fonts in the system changed from:

to:

I hope you can see the difference. The latter are "thinner". Also it seems the fonts in text fields changed to monospace (?):

I tried this to no avail. How to fix the font settings?
fc-cache-rv in the terminal (source: http://askubuntu.com/questions/577999/ubuntu-14-nautilus-font-is-wrong). – Greg Kramida Dec 17 '15 at 17:58